x86, dmar: routines for disabling queued invalidation and intr remapping

Impact: new interfaces (not yet used)

Routines for disabling queued invalidation and interrupt remapping.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>